The invention relates to a flexible all-steel shaft coupling comprising two connecting flanges and an intermediate piece arranged between the connecting flanges, with a disk ring being arranged between each of the two connecting flanges and the intermediate piece; said disk ring being connected alternately to the respective connecting flange and the intermediate piece, by means of circumferentially-distributed studs and tension sleeves, each comprising a radially protruding end stop, as well as spacer rings held on the tension sleeves, so that the connecting flanges are interconnected so as to be torsionally rigid but with angular movement and axial movement; with each of the studs connected to the connecting flanges being associated with only a single tension sleeve.
Such a shaft coupling is for example known from DE 34 43 485 A1. This coupling has basically proven reliable in practical experience. It has however been shown that due to its dimensions it cannot be installed, or only installed with difficulty, in conditions of confined space, between the extremities of the shafts to be connected.
It is thus the object of the invention to improve a shaft coupling of the type mentioned in the introduction, such that it is of compact design and can easily be installed and deinstalled in confined spaces.
With a generic shaft coupling this object is met in that each of the tension sleeves associated with the studs connected to the connecting flanges, comprises an internal screw thread for screwing the stud; that the intermediate piece is an intermediate ring; and that at each of the two connecting flanges, pairs of coupling shells are arranged, with the shell of each pair of coupling shells being constructed in a single piece together with the associated connecting flange.
The all-steel shaft coupling according to the invention is characterised by a very short and compact design, as well as by few individual components. It can be installed or deinstalled simply, in confined spaces, without the two shafts to be connected having to be moved apart in axial direction.
According to a preferred embodiment, the connection of the disk rings with the intermediate ring can take place in such a way that the studs connected to the intermediate ring are screwed into threaded bore holes provided in the intermediate ring. This embodiment does not require any nuts for attaching the studs associated with the intermediate ring, thus considerably facilitating installation or deinstallation of the coupling.
Another advantageous embodiment in relation to attachment of the disk rings to the intermediate ring is characterised in that the studs connected to the intermediate ring in each instance connect both disk rings to the intermediate ring. This embodiment provides the advantage of particularly fast installation because the intermediate ring can be attached with only a few screws between the preinstalled left coupling section and the preinstalled right coupling section. Preferably only three screws are required for installing or deinstalling the preinstalled coupling sections. Furthermore, this embodiment allows installation or deinstallation of the shaft coupling even where the space between the extremities of the shafts to be connected is small, as will be illustrated below by means of an exemplary embodiment.
According to another advantageous embodiment, the axial overall length of the shaft coupling according to the invention is kept small in particular when the heads of the studs connected to the connecting flanges are accommodated in a countersunk bore hole.
A further advantageous embodiment of the coupling according to the invention consists of those ends of the tension sleeves opposite the radially protruding end stop protruding with play into a borehole enlargement of the connecting flange or of the intermediate ring, and of the spacer rings being supported on the connecting flange or the intermediate ring. In this way installation of the coupling is further facilitated.
A particularly compact design of the shaft coupling according to the invention can be achieved if the connecting flanges and the intermediate ring comprise bore holes into which the end stops of the tension sleeves interact with play.
Another preferred embodiment of the shaft coupling according to the invention provides for one shell of each pair of coupling shells to comprise a groove for accommodating a feather key. In this way a positive-lock connection and thus a particularly safe torsionally rigid connection of the shaft ends is achieved.